Team Calendar - Resource Availability View (JSON?)

I work with a small team of consultants who are trying to transition our internal workflows from MS Excel sheets to Teams + SharePoint. One of the biggest challenges so far has been a master calendar that shows who is available when for capacity planning / work scheduling etc.

• Distributed team of about 6 people (multiple time zones)
• Projects are ~6 weeks long, require 2 people from my team as well as 1-3 others from within the organization, but not my team
• Vacation / leave is generally permissive - does not require extensive pre-approval

We need a consolidated view of commitments, availability etc. for at least the next quarter to support staffing / job planning etc. Is there a configuration of a SharePoint calendar that could provide a coarse-grained GANTT view or something similar? Perhaps the new JSON capabilities in modern lists could be used? I don't want to re-invent the wheel if something like this is already available.